/**
 * Loads a Wavefront .mtl file specifying materials
 *
 * @author angelxuanchang
 */

;(function (factory) {
  if (typeof define === "function" && define.amd) {
    // AMD模式
    define(["three"], factory);
  } else {
    // 全局模式
    factory(THREE);
  }
}(function (THREE) {

  THREE.MTLLoader = function( manager ) {

    this.manager = ( manager !== undefined ) ? manager : THREE.DefaultLoadingManager;

  };

  Object.assign( THREE.MTLLoader.prototype, THREE.EventDispatcher.prototype, {

    /**
     * Loads and parses a MTL asset from a URL.
     *
     * @param {String} url - URL to the MTL file.
     * @param {Function} [onLoad] - Callback invoked with the loaded object.
     * @param {Function} [onProgress] - Callback for download progress.
     * @param {Function} [onError] - Callback for download errors.
     *
     * @see setPath setTexturePath
     *
     * @note In order for relative texture references to resolve correctly
     * you must call setPath and/or setTexturePath explicitly prior to load.
     */
    load: function ( url, onLoad, onProgress, onError ) {

      var scope = this;

      var loader = new THREE.XHRLoader( this.manager );
      loader.setPath( this.path );
      loader.load( url, function ( text ) {

        onLoad( scope.parse( text ) );

      }, onProgress, onError );

    },

    /**
     * Set base path for resolving references.
     * If set this path will be prepended to each loaded and found reference.
     *
     * @see setTexturePath
     * @param {String} path
     *
     * @example
     *     mtlLoader.setPath( 'assets/obj/' );
     *     mtlLoader.load( 'my.mtl', ... );
     */
    setPath: function ( path ) {

      this.path = path;

    },

    /**
     * Set base path for resolving texture references.
     * If set this path will be prepended found texture reference.
     * If not set and setPath is, it will be used as texture base path.
     *
     * @see setPath
     * @param {String} path
     *
     * @example
     *     mtlLoader.setPath( 'assets/obj/' );
     *     mtlLoader.setTexturePath( 'assets/textures/' );
     *     mtlLoader.load( 'my.mtl', ... );
     */
    setTexturePath: function( path ) {

      this.texturePath = path;

    },

    setBaseUrl: function( path ) {

      console.warn( 'THREE.MTLLoader: .setBaseUrl() is deprecated. Use .setTexturePath( path ) for texture path or .setPath( path ) for general base path instead.' );

      this.setTexturePath( path );

    },

    setCrossOrigin: function ( value ) {

      this.crossOrigin = value;

    },

    setMaterialOptions: function ( value ) {

      this.materialOptions = value;

    },

    /**
     * Parses a MTL file.
     *
     * @param {String} text - Content of MTL file
     * @return {THREE.MTLLoader.MaterialCreator}
     *
     * @see setPath setTexturePath
     *
     * @note In order for relative texture references to resolve correctly
     * you must call setPath and/or setTexturePath explicitly prior to parse.
     */
    parse: function ( text ) {

      var lines = text.split( '\n' );
      var info = {};
      var delimiter_pattern = /\s+/;
      var materialsInfo = {};

      for ( var i = 0; i < lines.length; i ++ ) {

        var line = lines[ i ];
        line = line.trim();

        if ( line.length === 0 || line.charAt( 0 ) === '#' ) {

          // Blank line or comment ignore
          continue;

        }

        var pos = line.indexOf( ' ' );

        var key = ( pos >= 0 ) ? line.substring( 0, pos ) : line;
        key = key.toLowerCase();

        var value = ( pos >= 0 ) ? line.substring( pos + 1 ) : '';
        value = value.trim();

        if ( key === 'newmtl' ) {

          // New material

          info = { name: value };
          materialsInfo[ value ] = info;

        } else if ( info ) {

          if ( key === 'ka' || key === 'kd' || key === 'ks' ) {

            var ss = value.split( delimiter_pattern, 3 );
            info[ key ] = [ parseFloat( ss[ 0 ] ), parseFloat( ss[ 1 ] ), parseFloat( ss[ 2 ] ) ];

          } else {

            info[ key ] = value;

          }

        }

      }

      var materialCreator = new THREE.MTLLoader.MaterialCreator( this.texturePath || this.path, this.materialOptions );
      materialCreator.setCrossOrigin( this.crossOrigin );
      materialCreator.setManager( this.manager );
      materialCreator.setMaterials( materialsInfo );
      return materialCreator;

    }

  } );

  /**
   * Create a new THREE-MTLLoader.MaterialCreator
   * @param baseUrl - Url relative to which textures are loaded
   * @param options - Set of options on how to construct the materials
   *                  side: Which side to apply the material
   *                        THREE.FrontSide (default), THREE.BackSide, THREE.DoubleSide
   *                  wrap: What type of wrapping to apply for textures
   *                        THREE.RepeatWrapping (default), THREE.ClampToEdgeWrapping, THREE.MirroredRepeatWrapping
   *                  normalizeRGB: RGBs need to be normalized to 0-1 from 0-255
   *                                Default: false, assumed to be already normalized
   *                  ignoreZeroRGBs: Ignore values of RGBs (Ka,Kd,Ks) that are all 0's
   *                                  Default: false
   * @constructor
   */

  THREE.MTLLoader.MaterialCreator = function( baseUrl, options ) {

    this.baseUrl = baseUrl || '';
    this.options = options;
    this.materialsInfo = {};
    this.materials = {};
    this.materialsArray = [];
    this.nameLookup = {};

    this.side = ( this.options && this.options.side ) ? this.options.side : THREE.FrontSide;
    this.wrap = ( this.options && this.options.wrap ) ? this.options.wrap : THREE.RepeatWrapping;

  };

  THREE.MTLLoader.MaterialCreator.prototype = {

    constructor: THREE.MTLLoader.MaterialCreator,

    setCrossOrigin: function ( value ) {

      this.crossOrigin = value;

    },

    setManager: function ( value ) {

      this.manager = value;

    },

    setMaterials: function( materialsInfo ) {

      this.materialsInfo = this.convert( materialsInfo );
      this.materials = {};
      this.materialsArray = [];
      this.nameLookup = {};

    },

    convert: function( materialsInfo ) {

      if ( ! this.options ) return materialsInfo;

      var converted = {};

      for ( var mn in materialsInfo ) {

        // Convert materials info into normalized form based on options

        var mat = materialsInfo[ mn ];

        var covmat = {};

        converted[ mn ] = covmat;

        for ( var prop in mat ) {

          var save = true;
          var value = mat[ prop ];
          var lprop = prop.toLowerCase();

          switch ( lprop ) {

            case 'kd':
            case 'ka':
            case 'ks':

              // Diffuse color (color under white light) using RGB values

              if ( this.options && this.options.normalizeRGB ) {

                value = [ value[ 0 ] / 255, value[ 1 ] / 255, value[ 2 ] / 255 ];

              }

              if ( this.options && this.options.ignoreZeroRGBs ) {

                if ( value[ 0 ] === 0 && value[ 1 ] === 0 && value[ 2 ] === 0 ) {

                  // ignore

                  save = false;

                }

              }

              break;

            default:

              break;
          }

          if ( save ) {

            covmat[ lprop ] = value;

          }

        }

      }

      return converted;

    },

    preload: function () {

      for ( var mn in this.materialsInfo ) {

        this.create( mn );

      }

    },

    getIndex: function( materialName ) {

      return this.nameLookup[ materialName ];

    },

    getAsArray: function() {

      var index = 0;

      for ( var mn in this.materialsInfo ) {

        this.materialsArray[ index ] = this.create( mn );
        this.nameLookup[ mn ] = index;
        index ++;

      }

      return this.materialsArray;

    },

    create: function ( materialName ) {

      if ( this.materials[ materialName ] === undefined ) {

        this.createMaterial_( materialName );

      }

      return this.materials[ materialName ];

    },

    createMaterial_: function ( materialName ) {

      // Create material

      var scope = this;
      var mat = this.materialsInfo[ materialName ];
      var params = {

        name: materialName,
        side: this.side

      };

      var resolveURL = function ( baseUrl, url ) {

        if ( typeof url !== 'string' || url === '' )
          return '';

        // Absolute URL
        if ( /^https?:\/\//i.test( url ) ) {
          return url;
        }

        return baseUrl + url;
      };

      function setMapForType ( mapType, value ) {

        if ( params[ mapType ] ) return; // Keep the first encountered texture

        var texParams = scope.getTextureParams( value, params );
        var map = scope.loadTexture( resolveURL( scope.baseUrl, texParams.url ) );

        map.repeat.copy( texParams.scale );
        map.offset.copy( texParams.offset );

        map.wrapS = scope.wrap;
        map.wrapT = scope.wrap;

        params[ mapType ] = map;
      }

      for ( var prop in mat ) {

        var value = mat[ prop ];

        if ( value === '' ) continue;

        switch ( prop.toLowerCase() ) {

          // Ns is material specular exponent

          case 'kd':

            // Diffuse color (color under white light) using RGB values

            params.color = new THREE.Color().fromArray( value );

            break;

          case 'ks':

            // Specular color (color when light is reflected from shiny surface) using RGB values
            params.specular = new THREE.Color().fromArray( value );

            break;

          case 'map_kd':

            // Diffuse texture map

            setMapForType( "map", value );

            break;

          case 'map_ks':

            // Specular map

            setMapForType( "specularMap", value );

            break;

          case 'map_bump':
          case 'bump':

            // Bump texture map

            setMapForType( "bumpMap", value );

            break;

          case 'ns':

            // The specular exponent (defines the focus of the specular highlight)
            // A high exponent results in a tight, concentrated highlight. Ns values normally range from 0 to 1000.

            params.shininess = parseFloat( value );

            break;

          case 'd':

            if ( value < 1 ) {

              params.opacity = value;
              params.transparent = true;

            }

            break;

          case 'Tr':

            if ( value > 0 ) {

              params.opacity = 1 - value;
              params.transparent = true;

            }

            break;

          default:
            break;

        }

      }

      this.materials[ materialName ] = new THREE.MeshPhongMaterial( params );
      return this.materials[ materialName ];
    },

    getTextureParams: function( value, matParams ) {

      var texParams = {

        scale: new THREE.Vector2( 1, 1 ),
        offset: new THREE.Vector2( 0, 0 ),

      };

      var items = value.split(/\s+/);
      var pos;

      pos = items.indexOf('-bm');
      if (pos >= 0) {

        matParams.bumpScale = parseFloat( items[pos+1] );
        items.splice( pos, 2 );

      }

      pos = items.indexOf('-s');
      if (pos >= 0) {

        texParams.scale.set( parseFloat( items[pos+1] ), parseFloat( items[pos+2] ) );
        items.splice( pos, 4 ); // we expect 3 parameters here!

      }

      pos = items.indexOf('-o');
      if (pos >= 0) {

        texParams.offset.set( parseFloat( items[pos+1] ), parseFloat( items[pos+2] ) );
        items.splice( pos, 4 ); // we expect 3 parameters here!

      }

      texParams.url = items.join(' ').trim();
      return texParams;

    },

    loadTexture: function ( url, mapping, onLoad, onProgress, onError ) {

      var texture;
      var loader = THREE.Loader.Handlers.get( url );
      var manager = ( this.manager !== undefined ) ? this.manager : THREE.DefaultLoadingManager;

      if ( loader === null ) {

        loader = new THREE.TextureLoader( manager );

      }

      if ( loader.setCrossOrigin ) loader.setCrossOrigin( this.crossOrigin );
      texture = loader.load( url, onLoad, onProgress, onError );

      if ( mapping !== undefined ) texture.mapping = mapping;

      return texture;

    }

  };

}));

